Shank and bit punch



May 25,1926. 1,586,205

' H. LEVINE SHANK AND BIT PUNCH.

Filed .July 5, 1925 2 Sheets- Sheet 1 INVENTOR flymanlew'ne B ms ATTORNEY H. LEVINE SHANK' AND BIT PUNCH May 25 1926.

Filed July 5, 1925 2 Sheets-Sheet 2 INVENTOR fl nzunLez/i/ne ms 'ATTCRN Y Patented May 25,1926.

UNETEB HYMAN LEVINE, 01? DENVER, COLORADO, ASSIGNQR T0 INGEBSOLL-RAND COMPANY,

1,586,205 Parser series. v

OF JIElIIEtSEY CITY, NEl/V JERSEY, A CORPORATION OF NEW JERSEY.

'sHAn AND BIT PUNCH;

Application filed July 3,

This invention relates to shank and bit punches, but more particularly to that type of machine in which the punch pin is both hammered into and out ofthe drillsteel.

The objects of the invention are to enable a Variable stroke hammer to be used and automatically vary the length of the stroke of the hammer in accordance with the direction in which the pin is to be driven. i hen the pin is being driven out of the steel, the hammer stroke is automatically lengthened so that the hammer is permitted to strike the back head and the blows are transmitted to the front head and anvil block through the side rods.

The invention is shown in one of its preferred forms in the accompanying drawings, in which Figure 1 is a longitudinal sectional elevation of the machine,

Figure 2 is a similar view with the piston in a different position,

Figure 3 is a similar view showing-the pin being driven out of the drill steel, and

Figure 4: is a longitudinal sectional plan View on the line 44- of Figure 3 looking in the direction of the arrows.

Referring to the drawings, the hammer cylinder A, to which may be connected the pressure fluid feed cylinder B, is conveniently mounted on the slide or guide C and the piston rod D of the feed piston E is connected to the frame F. The drill steel G is held in any suitable clamping device or jaws H and J which may be the clamping jaws on the usual drill sharpener. The front head K and back head L of the hammer cylinder are connected by the usual side rods 0 and the front head K is recessed at P to receive the head Q of the anvil block R. A cap or cover S is provided for the front head and the pin T is held in the anvil block as by means of the key U. In the position of the parts shown in Figure 1, the striking portion V of the anvil block extends into the cylinder in the path of the piston W which in this instance is shown as a diflerential valveless piston having the head X, the neck Y and a rearward reduced extension having a rearward face Z.

A throttle valvea controls both the distribution of motive fluid to the hammer cylinder and to the feed cylinder B by means of suitable ports and passages. In the poslside 1925. Serial No. 41,270.

tion of the valve a in Figures 1 and 2, pressure fluid entering through the central portion 6 of the valve passes through the passage c in the cylinder to the rearward pressure surface Z of the piston W and during the operation of the piston, constant pressure is supplied to the rearward face Z. Pressure fluid is also supplied around the piston neck Y to the rearward face (Z of the piston head X to drive the piston forward and the forward end of the cylinder is exhausted through the exhaust port 6. hen the rearward end Z of the piston overruns the passage f, pressure fluid is supplied to the forward end of the piston to drive it rearwardly, and in Figure 2 the piston is shown movingrearwardly.

Pressure fluid is also supplied through the passage 9 to the forward end of the feed cylinder B and the rearward end of the' feed cylinder B is exhausted to the passage h and to atmosphere through the port j in the valve a. 7

While the hammer pistonlV is imparting blows of impact to the anvil block R to drive the pin into the drill steel, the com-l pression relief passage 76 leading from the rearward end of the enlarged bore of the cylinder to the front head K is closed at its forward. end because the head Q, of the anvil block closes the port- 0 in the front head which affords communication between the relief passage 7: and the chamber or recess P in the front head, which chamber is vented to atmosphere at the port 10. There is thus sufficient compression behind the enlarged head X of the piston W on its rearward stroke to prevent the rearward end Z of the piston from striking the back head L. The

compression behind the piston head X shortens the piston stroke automatically and prevents blows of impactbeing delivered by the piston to any part of the cylinder or back head, although the full force of the impact blow of the piston is delivered on the forward stroke upon the anvil block.

The throttle valve or is turned to the position indicated in Figure 3 in order to retract the machine and drive the pin out of the drill steel. Pressure fluid will be admitted through the passage h to the rearward end of the feed cylinder B and the forward end of the feed cylinder will be exhausted to atmosphere through the passage g and through the port 9 in the valve behind the enlarged head X or" the piston 1V is relieved to a sufiicient extent to permit the rear end Z or" the piston to strike against the back head L of the cylinder and thus transmit blows through the back head and side rods 0 to the front head K and thence to the anvil block It to drive the pin out of the drill steel.

The stroke of the piston is automatically shortened or lengthened in accordance with the direction in which the pin is to be driven.

I claim:

1. In a shank and bit punch for drill steels, the combination of means for holding the drill steel, a hammer cylinder, an anvil block mounted in said cylinder, :1 pin carried by the anvil block and adapted to enter the drill steel, a variable stroke fluid actuated hammer piston reciprocating in the cylinder, and means for automatically varyingthe length of the stroke of the hammer in accordance with the direction in which the pin is to be driven.

In a shank and bit punch for drill steels, the combination of means for holding the drill steel, a hammer cylinder, an anvil block mounted in said cylinder, a pin carried by the anvil block and adapted to en ter the drill steel, a variable stroke fluid actuated hammer piston reciprocating in the cylinder, and means for automatically lengthening the stroke of the hammer for driving the pin out of the drill steel.

3. In a shank and bit punch for drill steels, the combination oi means for holding the drill steel, a hammer cylinder, an anvil block nidunted in said cylinder, a pin carried by the anvil block and adapted to enter the drill steel, a variable stroke fluid actuated hammer piston reci 'irocating in the cylinder, cushioningmeans for preventing the hammer from striking the back head of the cylinder when the pin is being driven into the drill steel, and means for automatically relieving; said cushion to a sufficient extent to lengthen the hammer stroke and permit the hammer to strike the back head when the pin is being driven out of the drill steel.

4:. In a shank and bit punch for drill steels, the combination of means for holding the drill steel, a. hammer cylinder, an anvil block mounted in said cylinder, a pin carried by the anvil block and adapted to enter the drill steel, a variable stroke fluid :=.ctuated differential valveless hammer pis- 

